欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2021, Vol. 30 ›› Issue (1): 59-71.DOI: 10.11686/cyxb2020321

• 研究论文 • 上一篇    下一篇

羊草根际促生菌的分离筛选及促生作用研究

漫静1,2,3(), 唐波2,3, 邓波1(), 李佳欢1, 何玉娟1, 张佳良1   

  1. 1.中国农业大学草业科学与技术学院,北京 100193
    2.中国科学院植物研究所植被与环境变化国家重点实验室,北京 100093
    3.中国科学院大学资源与环境学院,北京 100049
  • 收稿日期:2020-07-07 修回日期:2020-09-07 出版日期:2021-01-20 发布日期:2021-01-08
  • 通讯作者: 邓波
  • 作者简介:Corresponding author. E-mail: dengbo@cau.edu.cn
    漫静(1993-),女,甘肃环县人,在读博士。E-mail: manjing@ibcas.ac.cn
  • 基金资助:
    国家重点研发计划“典型脆弱生态修复与保护研究专项:北方草甸退化草地治理技术与示范”(呼伦贝尔退化草甸草原综合治理技基金项目:术与模式“2016YFC0500603”)资助

Isolation, screening and beneficial effects of plant growth-promoting rhizobacteria (PGPR) in the rhizosphere of Leymus chinensis

Jing MAN1,2,3(), Bo TANG2,3, Bo DENG1(), Jia-huan LI1, Yu-juan HE1, Jia-liang ZHANG1   

  1. 1.College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China
    2.State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China
    3.College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2020-07-07 Revised:2020-09-07 Online:2021-01-20 Published:2021-01-08
  • Contact: Bo DENG

摘要:

植物根际促生菌(PGPR)是定殖在植物根际并且能够促进植物生长发育的一类有益细菌,本研究从不同地区的羊草根际分离筛选具有固氮、溶磷、分泌ACC脱氨酶和分泌生长素(IAA)能力的PGPR菌株,以期为研发PGPR为主的微生物肥料提供菌种资源。本研究从黑龙江兰西、内蒙古锡林浩特和呼伦贝尔3个地区共分离到20株具有固氮酶活性的固氮菌株,固氮酶活性范围为8.71~11.63 nmol C2H4·mL-1·h-1。通过PKO无机磷培养基和蒙金娜有机磷培养基从3个地区筛选出的溶磷圈直径与菌落直径比值(D/d值)大于1.5的溶解无机磷的PGPR和溶解有机磷的PGPR分别有26和36株,其溶磷量范围分别为7.08~82.71 μg·mL-1和1.56~32.48 μg·mL-1。筛选出60株具有ACC脱氨酶活性的PGPR菌株,酶活性范围为0.04~64.31 μmol α-KA·mg-1 Pr·h -1。挑选上述固氮酶活性较高、溶磷能力较强及ACC脱氨酶活性较高的39株PGPR菌株进行分泌IAA能力测定,结果表明这39株PGPR均具有分泌IAA的能力,分泌量范围为3.27~48.97 μg·mL-1。通过初步试管接种试验,本研究筛选出两株菌株HPS14和XPR2,可促进羊草生长。与对照 [株高、地上和地下生物量分别为(22.2±0.58) cm,(0.0461±0.0069) g和(0.0038±0.0007) g] 相比,接种菌株HPS14后羊草的株高、地上和地下生物量分别增加了49.0%,89.2%和243.1%;接种菌株XPR2后羊草的株高、地上和地下生物量分别增加了16.8%,28.9%和240.0%。经16S rRNA基因序列比对鉴定,这两株菌分别属于Inquilinus ginsengisoliPhyllobacterium loti。本研究结果可为后续PGPR微生物肥料的研制提供菌种资源和理论依据。

关键词: 羊草, 植物根际促生菌, 固氮菌, 溶磷菌, ACC脱氨酶

Abstract:

Plant growth-promoting rhizobacteria (PGPR) are a category of beneficial bacteria which colonize the plant rhizosphere and promote plant growth and development. In this study, PGPR strains with the capacity for nitrogen fixation, phosphate solubilization, ACC deaminase activity and IAA production were isolated and screened from the rhizosphere of Leymus chinensis in different regions, with a view to providing PGPR resources for the development of microbial fertilizers. Twenty strains possessing high nitrogenase activities (range 8.71 to 11.63 nmol C2H4 ·mL-1·h-1) were isolated from Lanxi, Xilinhot and Hulun Buir. Twenty six inorganic phosphorus solubilizing bacterial strains with ratios of the diameter of phosphate-solubilizing halo to colony diameter (D/d values) greater than 1.5 were identified. For these, the range of phosphate solubilization was 7.08-82.71 μg·mL-1. Thirty six organic phosphorus solubilizing bacteria with D/d values greater than 1.5 were also isolated with the range of phosphate-solubilization being 1.56-32.48 μg·mL-1. Sixty PGPR strains with ACC deaminase activities were screened and the range of activities observed were 0.04-64.31 μmol α-KA·mg-1 Pr·h-1. Thirty nine PGPR strains with high activities of nitrogenase, phosphate-solubilizing ability and ACC deaminase activity were further selected for determination of IAA production. The results showed that all 39 PGPR strains in this selection had the ability to secrete IAA, with the secretion amounts ranging from 3.27 to 48.97 μg·mL-1. Two strains (HPS14 and XPR2) which were observed to increase height and aboveground and belowground biomass of Leymus chinensis were screened out in an in vitro experiment. Compared with control plants (not inoculated with PGPR), the height, and aboveground and belowground dry weight of Leymus chinensis in a treatment inoculated with a PGPR strain named HPS14 were increased by 49.0%, 89.2% and 243.1%, respectively; and for plants inoculated with a PGPR strain named XPR2 were increased by 16.8%, 28.9% and 240.0%, respectively. 16S rRNA showed that these two strains belong to the species Inquilinus ginsengisoli and Phyllobacterium loti, respectively. These strains could be used for the development of microbial fertilizer.

Key words: Leymus chinensis, plant growth-promoting rhizobacteria, nitrogen fixing bacteria, phosphorus solubilizing bacteria, 1-aminocyclopropane-1-carboxylic acid deminase